Sjögren’s syndrome is a chronic multisystem inflammatory autoimmune disorder characterized by a combination of dry eyes and dry mouth. It is estimated that the annual incidence of Sjogren’s may range between four to as high as 43 per 100,000 people, with approximately five percent of these patients having severe dry eye. Severe dry eye is a painful and debilitating symptom that can lead to blindness.
Sjögren’s syndrome affects multiple organs, including the eye where it is responsible for a very severe form of dry eye which can be sight threatening. It is estimated that dry eye disease generally affects approximately 8% of the population, mainly women, and in 11% of these it is a co-morbidity of Sjögren’s syndrome. Thus approximately 2.5 million people in the United States suffer from ocular Sjögren’s syndrome. The only approved drug for dry eye (but not Sjögren’s syndrome), cyclosporine, is of limited efficacy against ocular Sjögren’s syndrome.
Coversin has successfully completed a 60 day topical eye toxicology study, and there is evidence that Coversin has activity against eye surface inflammation. Delivery by the topical ocular route, made possible by Coversin’s small molecular size, has considerable advantages both in reducing the total quantity of drug needed and, because the very small topical dose, virtually abolishes the effects of systemic complement inhibition, in reducing the risk of meningitis infection or need for prophylaxis of potential Neisseria infections.
Coversin’s special physical characteristics make it an attractive candidate drug for the treatment of Sjögren’s syndrome, which is not accessible by this route to antibodies like eculizumab or gene therapies, which require systemic complement inhibition. Relative to systemic diseases such as PNH and aHUS, ocular drug development is potentially rapid and new drugs typically gain marketing approval much sooner than their systemic counterparts.